The seasonal variation of deaths in Finland during the period 1961-1995, and its possible diminution over time was examined on a daily and monthly basis. The daily pattern of deaths over the year was asymmetric, with a very steep rise in December (peak on December 26), a slow rise in late winter and spring, a secondary rise in June (peak on June 24) and a trough in late August. The December peak was 26% higher than the August trough and showed no diminution over the period studied. The second peak in June was 12% higher than the annual minimum and was particularly pronounced in deaths from ischaemic heart disease and among people dying at ages 35 to 64 years. The winter excess in all natural mortality was estimated to be 7.4% of all annual deaths, and it showed some diminution over time, from 8.4% in 1961 to 6.3% in 1995, mainly because of the steeper decline in mortality in late winter in the 1980s and 1990s compared with the previous periods.